"I'm not ready to give up my full frame bodies, but I'm loving this lens. The great image quality seals the deal for the Sigma 18-35mm f/1.8 DC HSM A Lens. The results that this lens is capable of delivering are impressive."Read full review

f/1.8 seems impressive until you consider the fact that cameras with smaller sensors need the extra aperture to compensate for inherently deeper depth of field. It's a lot like a 29-56mm f/2.5 in full-frame terms.

If you already have a 24-70 f/2.8 on FF, this lens won't seem that tempting, but if you have no need to go FF, then you now have a lens that can give you similar performance for only $800.

I thought I came across a thread a while back that this lens work with a 5d3 with minimal vignetting.

Probably going to be rather soft in the corners... someone needs to test it out to see the degree of usability.

Kolor-Pikker wrote:
f/1.8 seems impressive until you consider the fact that cameras with smaller sensors need the extra aperture to compensate for inherently deeper depth of field. It's a lot like a 29-56mm f/2.5 in full-frame terms.

I'm more often stopping down on FF to get adequate DOF than I am opening up to get less, particularly for the closer proximity shooting I do in this focal range. For my type of shooting this lens is without peer.

Kolor-Pikker wrote:
Probably going to be rather soft in the corners... someone needs to test it out to see the degree of usability.

The review suggests that the corners are not soft: "Another factor making the relatively short focal length range more palatable is the image quality this lens delivers. Especially at f/1.8 where this lens delivers very good sharpness across the entire frame."

snapsy wrote:
I'm more often stopping down on FF to get adequate DOF than I am opening up to get less, particularly for the closer proximity shooting I do in this focal range. For my type of shooting this lens is without peer.

So much confusion in one post...

Are you saying that having an 18-35/1.8 lens stopped down is preferable to having an F/2.8 covering the same focal length?

zlatko wrote:
The review suggests that the corners are not soft: "Another factor making the relatively short focal length range more palatable is the image quality this lens delivers. Especially at f/1.8 where this lens delivers very good sharpness across the entire frame."

Yes it have good sharpness across the entire frame. But that's with a crop body. The quote you replied to talked about a 5D3. And those black corners with a 5D3 will not have good sharpness

I don't know what's going on with the guys at Sigma, but they've certainly took the game to the next level. Nikon/Canon will have to think twice before announcing and pricing a new lens, not that they will

I like this lens- a lot. I'm keeping my eye on crop camera and lens developments, and this lens, along with Sigma's other APS-C zooms, is very interesting.

My primary interest in this lens is that it provides incredible sharpness at every focal length it touches, thus replacing essentially every prime in that range on a crop system.

Other than the limiting focal range, I don't see a downside to this lens- even the price is pretty incredible. The real question I have about it is not how well it performs on crop cameras compared to other lenses in it's range on the same cameras, but rather how well it compares to a standard F/2.8 zoom on an FF camera- that is, compared to Canon's 24-70/2.8L II, or Tamron's 24-70/2.8 VC, across the focal length range, at different focal distances, in different situations, across the frame, etc.

Assuming equal sensor technology this lens on a crop will have about a 1/3 stop light advantage over the FF equivalent, provided its as sharp at f/1.8 vs the Canon 24-70 II at f/2.8, at the equivalent FOV and DOF. Perhaps even a little more than 1/3 stop considering the t-stop of the Signa has been measured at a full T1.8.

snapsy wrote:
Assuming equal sensor technology this lens on a crop will have about a 1/3 stop light advantage over the FF equivalent, provided its as sharp at f/1.8 vs the Canon 24-70 II at f/2.8, at the equivalent FOV and DOF. Perhaps even a little more than 1/3 stop considering the t-stop of the Signa has been measured at a full T1.8.

Sure; and that's the test I'd like to see. Particularly between the 70D, D7100, 5D III, and D800.

But I don't think that it would best a great standard zoom on an FF camera; but even if it does, it still lacks IS (which apparently they're working on next) along with a narrow focal length.

My main personal interest in this lens is that I'd like to pick up a crop body for action and reach; and I think that this lens would make an excellent companion for my full-frame uses.

Fred should institute an auto filter-and-replace forum routine. Every time the equivalency argument comes up, it should instead change the poster's text to :

I LIKE SOGGY MONKEY KITTENS AND CHEESE.

Looking at the full aperture range page, then the FF results.......this lens could essentially serve as both 28mm and 35mm f/1.8 lenses on FF with minimal vignetting except the very tippy corners, but TDP doesn't mention whether that series is shot wide open or not.

snapsy wrote:
Assuming equal sensor technology this lens on a crop will have about a 1/3 stop light advantage over the FF equivalent, provided its as sharp at f/1.8 vs the Canon 24-70 II at f/2.8, at the equivalent FOV and DOF. Perhaps even a little more than 1/3 stop considering the t-stop of the Signa has been measured at a full T1.8.

Hm, f/2.8 is equivalent to f/1.75 with the 1.6 crop factor.

I would like to se a comparison between this lens on a 24 MP Nikon APS-C vs the Tamron 24-70 2.8 VC on a Nikon 24 MP Full frame. All bets are that optically the larger system is better.

cputeq wrote:
this lens could essentially serve as both 28mm and 35mm f/1.8 lenses on FF with minimal vignetting except the very tippy corners, but TDP doesn't mention whether that series is shot wide open or not.
Yeah, though, in the Canon system, 28mm f/1.8 is fairly cheap, as is 35mm f/2. I can also get 35mm f/2 with IS for about the price of this lens.

Really, where this lens shines is 18-23mm f/1.8, where no other manufacturer is within a stop, and where even Sigmas 20mm f/1.8 is weak. So full-frame kind of wastes that

othfilm wrote:
Yeah, though, in the Canon system, 28mm f/1.8 is fairly cheap, as is 35mm f/2. I can also get 35mm f/2 with IS for about the price of this lens.

Really, where this lens shines is 18-23mm f/1.8, where no other manufacturer is within a stop, and where even Sigmas 20mm f/1.8 is weak. So full-frame kind of wastes that

I get the comparisons using it on FF; it's still a 35/1.8 on FF, which can be useful if you have both systems; I don't have anything close to that, and while I'm genuinely interested in one of the three great 35mm primes (35L, 35 IS, 35 Art), having this lens for a crop system might make up for that when placed on either an FF or crop camera. The price is certainly in line!